Severe eosinophilic asthma: from the pathogenic role of interleukin-5 to the therapeutic action of mepolizumab

Real-life rapidity of benralizumab effects in patients with severe allergic eosinophilic asthma: Assessment of blood eosinophils, symptom control, lung function and oral corticosteroid intake after the first drug dose

Benralizumab is a humanized monoclonal antibody which binds to the α subunit of the interleukin-5 (IL-5) receptor and to the FcγRIIIa receptor expressed by natural killer cells, thus suppressing the pro-eosinophil actions of IL-5 and triggering eosinophil apoptosis via the very effective mechanism of antibody-dependent cell-mediated cytotoxicity (ADCC). Because of its recent approval and introduction in clinical practice for the add-on biological therapy of severe eosinophilic asthma, real-life investigations are still lacking. In this regard, our present real-life study refers to 13 patients with severe allergic eosinophilic asthma, currently under treatment with benralizumab at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy. Already 4 weeks after the first subcutaneous injection of benralizumab at the dosage of 30 mg, blood eosinophil count rapidly dropped down from 814.7 ± 292.3 cells/μL to 51.3 ± 97.5 cells/μL (p < 0.0001). This relevant hematologic change was associated with quick and significant increases in asthma control test (ACT) score (from 15.31 ± 2.78 to 21.15 ± 3.58; p < 0.0001), pre-bronchodilator forced expiratory volume in 1 s (FEV₁) (from 1441 ± 757.9 mL to 1887 ± 837.3 mL; p < 0.001), and morning peak expiratory flow (PEF) (from 4.21 ± 2.20 to 5.33 ± 1.99 L/sec; p < 0.01). Furthermore, the marked improvement in global health status experienced by our patients allowed them to progressively lower and then completely interrupt, within 4 weeks, their daily intake of oral corticosteroids (OCS), which thereby fell from 15.58 ± 8.30 to 0 mg (p < 0.0001) of prednisone. Therefore, such preliminary results suggest that in patients with severe allergic eosinophilic asthma benralizumab can exert, within a real-life context, a very rapid and effective therapeutic action, already detectable 4 weeks after the first drug administration.

Impact of exacerbations on St George's Respiratory Questionnaire score in patients with severe asthma: post hoc analyses of two clinical trials and an observational study

Objective: To assess the effect of asthma exacerbations and mepolizumab treatment on health status of patients with severe asthma using the St George's Respiratory Questionnaire (SGRQ).Methods: Post hoc analyses were conducted using data from two randomized controlled trials in patients ≥12 years old with severe eosinophilic asthma randomized to receive placebo or mepolizumab 75 mg intravenously (32-week MENSA study) or 100 mg subcutaneously (MENSA/24-week MUSCA studies), and an observational single-visit study in patients with severe asthma (IDEAL). Linear regression models assessed the impact of historical exacerbations on baseline SGRQ total and domain scores (using data from each of the three studies), and within-study severe exacerbations and mepolizumab treatment on end-of-study SGRQ scores (using data from MENSA/MUSCA).Results: Overall, 1755 patients were included (MENSA, N = 540; MUSCA, N = 551; IDEAL, N = 664). In all studies, higher numbers of historical exacerbations were associated with worse baseline SGRQ total scores. Each additional historical exacerbation (beyond the second [MENSA/MUSCA]) or first [IDEAL] was associated with worsening mean total SGRQ scores of +1.5, +1.1 at baseline and +2.3 within the year prior to study enrollment. During MENSA and MUSCA, each within-study severe exacerbation was associated with a worsening in total SGRQ score of +2.4 and +3.4 points at study end. Independent of exacerbation reduction, mepolizumab accounted for an improvement in total SGRQ score of -5.3 points (MENSA) and -6.2 points (MUSCA).Conclusions: These findings support an association between a higher number of exacerbations and worse health status in patients with severe (eosinophilic) asthma.

Effectiveness and safety of mepolizumab in severe refractory eosinophilic asthma: results in clinical practice

Background

Asthma is an inflammatory disease of the airways with symptoms that vary over time and intensity, sometimes leading to disability or even death. Eosinophilic asthma accounts for 25% of cases of severe asthma. It is mediated by eosinophils regulated by interleukin-5 (IL-5), the target of mepolizumab, which has been recently licensed as an add-on treatment of severe refractory eosinophilic asthma. The aim of this study was to evaluate the effectiveness and safety of mepolizumab in clinical practice.

Methods

A multicentre, retrospective, and descriptive study covering a year was conducted in a province of Spain with more than 500,000 inhabitants. Every patient prescribed with mepolizumab since its introduction into the hospital was included in the study. Clinical parameters were collected from the pharmacists' counselling reports from electronic prescription software and electronic patient records. Effectiveness was assessed as a decrease in the exacerbation frequency and/or a reduction in the use of oral corticosteroids (OCS) compared to the previous year.

Results

A total of 25 patients were studied, but only 23 could be evaluated by the cut-off date. A decrease in the exacerbation frequency was observed in 19 (82.6%) patients, 11 of them without any exacerbation during the treatment. A relative reduction of 87% in the exacerbation rate per year was obtained. A total of 15 patients were on regular OCS - 9 patients (60%) reduced their average dose, whilst 4 (26.7%) patients completely abandoned OCS. Safety was evaluated based on reported adverse effects. Adverse events were observed in 12 patients, the most common being headache, arthralgia, and dizziness/nausea.

Conclusion

Mepolizumab has been shown to be effective based on the high decrease in the exacerbation frequency and reduced use of OCS. Reported adverse effects were mostly mild and appeared in half of the patients; some of the adverse events had not been previously described in pivotal trials.

Cerebral involvement in systemic vasculitides: Extracts from the guideline of the German neurological society

Cerebral vasculitis is a rare disorder but plays a major role in the differential diagnosis of stroke, encephalopathy and headache. This guideline was developed in order to support clinicians in the diagnosis and treatment of cerebral manifestations of systemic vasculitides and rheumatic diseases. It is based on a medline research and was developed in a modified Delphi process and approved by the involved societies. This article is an abridged and translated version of the guideline published in DGNeurologie: Berlit, P. & Krämer, M. DGNeurologie (2018) 1: 17. 10.1007/s42451-018-0001-y.

Efficacy and steroid-sparing effect of benralizumab: has it an advantage over its competitors?

Severe refractory asthma is characterized by a higher risk of asthma-related symptoms, morbidities, and exacerbations. This disease also determines much greater healthcare costs and deterioration in health-related quality of life (HR-QoL). Another concern, which is currently much discussed, is the high percentage of patients needing regular use of oral corticosteroids (OCS), which can lead to several systemic side effects. Airway eosinophilia is present in the majority of asthmatic patients, and elevated levels of blood and sputum eosinophils are associated with worse control of asthma. Regarding severe refractory eosinophilic asthma, interleukin-5 (IL-5) plays a fundamental role in the inflammatory response, due to the profound effect on eosinophils biology. The advent of the biological therapies provided an effective strategy, even if the increased number of molecules with different targets raised the challenge of choosing the right therapy and avoid overlapping. When considering severe refractory eosinophilic asthma and anti-IL-5 treatments, it is not easy to define which drug to choose between mepolizumab, reslizumab, and benralizumab.

In this article, we carried out an indirect comparison among literature data, especially between OCS reduction studies (ZONDA-SIRIUS) and pivotal studies (SIROCCO-MENSA), evaluating whether the clinical efficacy and the steroid-sparing effect of benralizumab may represent an advantage over other compounds. This data could help the clinician in the decision process of treatment choice, within the different available therapeutic options for eosinophilic refractory severe asthma.

S-Allyl cysteine reduces eosinophilic airway inflammation and mucus overproduction on ovalbumin-induced allergic asthma model

S-Allyl cysteine (SAC) is an active component in garlic and has various pharmacological effects, such as anti-inflammatory, anti-oxidant, and anti-cancer activities. In this study, we explored the suppressive effects of SAC on allergic airway inflammation induced in an ovalbumin (OVA)-induced asthma mouse model. To induce asthma, BALB/c mice were sensitized to OVA on days 0 and 14 by intraperitoneal injection and exposed to OVA from days 21 to 23 using a nebulizer. SAC was administered to mice by oral gavage at a dose of 10 or 20 mg/kg from days 18 to 23. SAC significantly reduced airway hyperresponsiveness, inflammatory cell counts, and Th2 type cytokines in bronchoalveolar lavage fluid induced by OVA exposure, which was accompanied by reduced serum OVA-specific immunoglobulin E. In histological analysis of the lung tissue, administration of SAC reduced inflammatory cell accumulation into lung tissue and mucus production in airway goblet cells induced by OVA exposure. Additionally, SAC significantly decreased MUC5AC expression and nuclear factor-κB phosphorylation induced by OVA exposure. In summary, SAC effectively suppressed allergic airway inflammation and mucus production in OVA-challenged asthmatic mice. Therefore, SAC shows potential for use in treating allergic asthma.

Therapeutic Effects of Human Umbilical Cord Mesenchymal Stromal Cells in Sprague-Dawley Rats with Percutaneous Exposure to Sulfur Mustard

Sulfur mustard (SM) exposure, whose symptoms are similar to radiation exposure, can lead to acute injury. Because mesenchymal stromal cells (MSCs) have been used to experimentally and clinically treat acute radiation syndrome, in this study, MSCs were intravenously injected into rats after percutaneous SM exposure. Then, we examined sternum and spleen samples by histopathological and immunohistochemical methods to observe pathological changes. Furthermore, blood samples were taken to test the white blood cell (WBC) count, blood platelet count (BPC), red blood cell count, and the levels of cytokines in the serum. The number of bone marrow karyocytes and the WBC in the MSC + SM group were higher than those in the SM group, and the levels of granulocyte colony-stimulating factor, granulocyte-macrophage colony stimulating factor, monocyte chemoattractant protein-1, interleukin (IL)-1α, IL-5, and interferon-γ in the MSC + SM group remained high at different time points after SM exposure. In addition, the BPC, the level of erythropoietin and the relative weight of the spleen in the MSC + SM group were significantly higher than those in the SM group. Meanwhile, spleens in the MSC + SM group were more hyperplastic and hematopoietic, and had fewer apoptotic cells than in the SM group. Furthermore, rat body weight and locomotion ability in the MSC + SM group were higher than in the SM group. This evidence supports the potential ability of MSCs in immunoregulation and functional improvements to the hemopoietic microenvironment. Intravenous injection of MSCs exerted significant therapeutic effects in rats with percutaneous exposure to SM.

Omalizumab lowers asthma exacerbations, oral corticosteroid intake and blood eosinophils: Results of a 5-YEAR single-centre observational study

Omalizumab is a humanized monoclonal antibody which binds to human immunoglobulins E (IgE), thus preventing their interactions with both high affinity and low affinity IgE receptors. Therefore, omalizumab is currently recommended for add-on biological therapy of uncontrolled allergic asthma, mainly characterized by type 2 airway eosinophilic inflammation. Because omalizumab has been the first, and for a long time the only available monoclonal antibody for add-on treatment of type 2 asthma, some long-term studies have been published which provide a clear evidence of the therapeutic effectiveness of the anti-IgE pharmacological strategy. Within this context, the present single-centre observational study refers to 15 patients with severe allergic asthma, treated with omalizumab for at least 5 years at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy. In these asthmatic subjects we observed significant increases in asthma control test (ACT) score, with respect to baseline (14.60 ± 2.97), after 1 year (19.20 ± 2.98; p < 0.0001) and 5 years (21.67 ± 2.38; p < 0.0001) of add-on treatment with omalizumab. More importantly, omalizumab significantly lowered the number of annual asthma exacerbations (baseline: 3.66 ± 2.01) after 1 year (0.83 ± 1.14; p < 0.0001) and 5 years (0.63 ± 0.99; p < 0.0001), respectively. This excellent therapeutic outcome made it possible to drastically decrease the daily oral intake of prednisone (baseline: 22.50 ± 5.17 mg) after 1 year (1.83 ± 4.06 mg; p < 0.0001), as well as after 5 years (1.66 ± 3.61 mg; p < 0.0001). With regard to lung function, omalizumab significantly and persistently enhanced FEV₁ (baseline: 1636 ± 628.4 mL) after 1 year (2000 ± 679.7 mL; p < 0.05) and 5 years (1929 ± 564.8 mL; p < 0.05), respectively. Such relevant clinical and functional improvements were associated with reductions of blood eosinophil counts (baseline: 646.0 ± 458.9 cells/μl), already detectable after 1 year (512.7 ± 327.8 cells/μl; not significant), which reached the threshold of statistical significance after 5 years (326.0 ± 171.8 cells/μl; p < 0.05). Therefore, these real-life data referring to our single-centre observational investigation further corroborate the long-term therapeutic ability of omalizumab to improve several clinical, functional and haematological signatures of severe type 2 asthma.

Real-life evaluation of the clinical, functional, and hematological effects of mepolizumab in patients with severe eosinophilic asthma: Results of a single-centre observational study

Mepolizumab is a humanized monoclonal antibody which targets interleukin-5 (IL-5) and is nowadays available in many countries for add-on biological therapy of severe eosinophilic asthma. Although the approval of mepolizumab use in clinical practice has been made possible by several successful pre-marketing controlled trials, so far only a very few studies have been performed in a real-life setting. Within such a context, our present observational investigation refers to 14 patients with refractory eosinophilic asthma, currently treated with mepolizumab at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy, whose anti-IL-5 treatment began between June 2017 and January 2018. These patients experienced a significant increase in asthma control test (ACT) score, that was evaluated at baseline (13.64 ± 3.00), as well as after 4 weeks (18.86 ± 3.15; p < 0.0001) and 24 weeks (20.07 ± 1.94; p < 0.0001) of add-on therapy with mepolizumab. This relevant improvement in symptom control was paralleled by a dramatic fall of blood eosinophil numbers, counted at baseline (647.1 ± 274.7 cells/μl), and at the 4th (147.8 ± 66.5 cells/μl; p < 0.0001) and 24th week (98.6 ± 40.3 cells/μl; p < 0.0001) after starting add-on treatment with mepolizumab. These changes were associated with significant and stable increases in FEV₁, which was recorded at baseline (1389 ± 454.3 mL), as well as after 4 weeks (1711 ± 482.3 mL; p < 0.001) and 24 weeks (1701 ± 456.0 mL; p < 0.01). Moreover, in comparison to the 6 months preceding the beginning of treatment with mepolizumab, after 24 weeks of anti-IL-5 therapy significant decreases were detected with regard to exacerbation numbers (from 3.64 ± 1.86 to 1.0 ± 0.78; p < 0.001) and oral intake of prednisone (from 24.11 ± 10.36 mg/day to 1.78 ± 3.82 mg/day). Therefore, these preliminary data referring to our single-centre observational study corroborate, in a real-life environment, the efficacy of mepolizumab for treatment of patients with exacerbation-prone, corticosteroid-refractory, severe eosinophilic asthma.

Benralizumab: From the Basic Mechanism of Action to the Potential Use in the Biological Therapy of Severe Eosinophilic Asthma

Asthma is a very frequent chronic airway disease that includes many different clinical phenotypes and inflammatory patterns. In particular, eosinophilic bronchial inflammation is often associated with allergic as well as nonallergic asthma. The most important cytokine involved in the induction, maintenance, and amplification of airway eosinophilia in asthma is interleukin-5 (IL-5), released by both T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells (ILC2). Hence, IL-5 and its receptor are suitable targets for selective biologic drugs which can play a key role in add-on treatment of severe eosinophilic asthma refractory to corticosteroids. Within such a context, the anti-IL-5 monoclonal antibodies mepolizumab and reslizumab have been developed and approved for biological therapy of uncontrolled eosinophilic asthma. In this regard, on the basis of several successful randomized controlled trials, the anti-IL-5 receptor benralizumab has also recently obtained the approval from US Food and Drug Administration (FDA).

Benralizumab in the treatment of severe asthma: design, development and potential place in therapy

Asthma is a widespread and heterogeneous inflammatory disease of the airways, which is characterized by several different phenotypes and endotypes. In particular, eosinophilic airway inflammation is a common pathologic trait of both allergic and nonallergic asthma. The key cytokine responsible for maturation, activation, recruitment, and survival of eosinophils is interleukin (IL)-5, which is mainly produced by T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells. Therefore, for uncontrolled patients with severe eosinophilic asthma, who are not fully responsive to corticosteroids, IL-5 represents a very important molecular target for add-on biological therapies. Among these new treatments, anti-IL-5 monoclonal antibodies such as mepolizumab and reslizumab have been developed and clinically evaluated. Furthermore, benralizumab is currently the only available biologic drug that specifically binds to the IL-5 receptor, thus preventing the interaction with its ligand and the consequent pro-inflammatory effects. The effectiveness of benralizumab in improving severe eosinophilic asthma has been well-documented by many randomized controlled trials.

Reslizumab in the treatment of severe eosinophilic asthma: an update

A marked heterogeneity is exhibited by asthma both clinically and at the molecular level with different phenotypes driven by diverse mechanistic pathways that require specifically targeted treatments. Biologics aimed at IL-4/13, IL-5 or IgE are proven or potentially effective treatments for patients with difficult to treat eosinophilic asthma. Importantly, it is now widely accepted that biologic-based therapies give significant clinical improvements in those patient populations where asthma phenotypes are taken into account. Such asthma phenotypes have been identified by reproducible and straightforward discriminatory biomarkers. This short review discusses recent studies of the effectiveness of the anti-IL-5 reslizumab in relation to the use of simple reproducible biomarkers in eosinophilic asthma.

Cytokine-targeting biologics for allergic diseases

OBJECTIVE

Asthma and allergic diseases continue to increase in prevalence, creating a financial burden on the health care system and affecting the quality of life for those who have these diseases. Many intrinsic and extrinsic factors are involved in the initiation and maintenance of the allergic response. Cytokines are proteins with growth, differentiation, and activation functions that regulate and direct the nature of immune responses.

DATA SOURCES

clinicaltrials.gov and PubMed.

STUDY SELECTIONS

Relevant clinical trials and recent basic science studies were chosen for discussion.

RESULTS

Many cytokines have been implicated in the development and perpetuation of the allergic response. Biologics have been and are continuing to be developed that target these molecules for use in patients with asthma and atopic dermatitis where standard treatment options fail. The current state of cytokine-targeting therapies is discussed.

CONCLUSION

This review focused on cytokines involved in the allergic response with an emphasis on those for which therapies are being or have been developed.

Omalizumab, the first available antibody for biological treatment of severe asthma: more than a decade of real-life effectiveness

Omalizumab was the first, and for a long time the only available monoclonal antibody for the add-on treatment of severe allergic asthma. In particular, omalizumab selectively targets human immunoglobulin (Ig)E, forming small-size immune complexes that inhibit IgE binding to its high- and low-affinity receptors. Therefore, omalizumab effectively blunts the immune response in atopic asthmatic patients, thus significantly improving the control of asthma symptoms and successfully preventing disease exacerbations. These very positive effects of omalizumab make it possible to drastically decrease both referrals to the emergency room and hospitalizations for asthma exacerbations. Such important therapeutic actions of omalizumab have been documented by several randomized clinical trials, and especially by more than 10 years of real-life experience in daily clinical practice. Omalizumab can also interfere with airway remodelling by inhibiting the activation of IgE receptors located on structural cells such as bronchial epithelial cells and airway smooth muscle cells. Moreover, omalizumab is characterized by a very good safety and tolerability profile. Hence, omalizumab represents a valuable therapeutic option for the add-on biological treatment of severe allergic asthma.